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Apple would be legally restricted from disclosing any government compromises, while still claiming their systems are secure and operating as intended in general

Apple would be legally restricted from disclosing any government compromises, while still claiming their systems are secure and operating as intended in general. We already know it's happening right now, and they know we know, but we can't do shit about it.

alwillis 18d ago
> Apple would be legally restricted from disclosing any government compromises, while still claiming their systems are secure and operating as intended in general. I'm aware. The point is they can't give the NSA something they don't have. The photo sensor generates its own ECDSA P-256 signing key pair and never releases the private half. Every device has a unique key pair and the private key is unavailable… there's not a way to give the NSA that would help them. The system is setup so that the image data, meta data, etc can't be accessed by anyone including Apple.
- microtonal 18d ago
  I believe them, but the process is hard to check. How do we verify that they don’t have the sensor burn in a private key generated by them? (Similar to how many PGP hardware keys allow generating a private key on-device or writing your own provided key.)
alwillis 18d ago
Here's a flow chart; tell us at what point there's something Apple can be compelled by a 3-letter organization to produce: https://news.ycombinator.com/item?id=49735284 https://news.ycombinator.com/item?id=49735284
- microtonal 18d ago
  I think the chart exactly shows the weakness that some people have pointed out. Apple's PCC servers at some point in time know the signing identity for a photo and Apple's generated replacement signature. The relevant steps from your chart: - verifies each link and its certificate chain, sensor signature over pixels, SEP signature, device manifest signature - PCC Submits the commitment (the JPEG hash) to Apple's signing service. So, at some point in time, Apple's servers have both the original certificate chain and the new replacement signature. If this is recorded, Apple can deanonimize photos and check whether two photos were from the same device/sensor. Apple's system protects against most state actors, except Apple and the US, unless you fully trust that their PCC is watertight. (Remember that Apple was part of PRISM and probably also its successor.) I don't think law enforcement needs it, because when sending/posting a picture, people leak so much metadata anyway. But people outside the US should certainly distrust these systems.

alwillis 18d ago

> Apple would be legally restricted from disclosing any government compromises, while still claiming their systems are secure and operating as intended in general. I'm aware. The point is they can't give the NSA something they don't have. The photo sensor generates its own ECDSA P-256 signing key pair and never releases the private half. Every device has a unique key pair and the private key is unavailable… there's not a way to give the NSA that would help them. The system is setup so that the image data, meta data, etc can't be accessed by anyone including Apple.

microtonal 18d ago
I believe them, but the process is hard to check. How do we verify that they don’t have the sensor burn in a private key generated by them? (Similar to how many PGP hardware keys allow generating a private key on-device or writing your own provided key.)

alwillis 18d ago

Here's a flow chart; tell us at what point there's something Apple can be compelled by a 3-letter organization to produce: https://news.ycombinator.com/item?id=49735284 https://news.ycombinator.com/item?id=49735284

microtonal 18d ago
I think the chart exactly shows the weakness that some people have pointed out. Apple's PCC servers at some point in time know the signing identity for a photo and Apple's generated replacement signature. The relevant steps from your chart: - verifies each link and its certificate chain, sensor signature over pixels, SEP signature, device manifest signature - PCC Submits the commitment (the JPEG hash) to Apple's signing service. So, at some point in time, Apple's servers have both the original certificate chain and the new replacement signature. If this is recorded, Apple can deanonimize photos and check whether two photos were from the same device/sensor. Apple's system protects against most state actors, except Apple and the US, unless you fully trust that their PCC is watertight. (Remember that Apple was part of PRISM and probably also its successor.) I don't think law enforcement needs it, because when sending/posting a picture, people leak so much metadata anyway. But people outside the US should certainly distrust these systems.